How Barcelona's Housing Registry Ended Up Drowning in Duplicate Listing Images — and What the City Is Doing About It

Barcelona's municipal housing registry holds photographs for more than 140,000 residential units — and an unknown but substantial share of those images appear more than once, sometimes attached to entirely different addresses. The problem surfaced publicly in late 2025 when Habitatge Metropolità de Barcelona, the agency overseeing the city's social housing allocation lists, flagged inconsistencies that were slowing down apartment inspections tied to Mayor Jaume Collboni's short-term rental crackdown.

The issue matters right now because the city is in the middle of its most aggressive push in years to enforce Law 18/2007, Catalonia's right-to-housing statute, while simultaneously trying to wind down the roughly 10,000 tourist apartment licences that Collboni's administration committed to eliminating by 2028. Both enforcement streams rely heavily on cross-referenced visual records. A duplicate image — the same façade photograph linked to a flat in Gràcia and another in Sant Pere — can cause automated verification tools to flag legitimate properties as already inspected, letting non-compliant landlords slip through.

The Digital Paper Trail That Created the Mess

The roots go back at least a decade. Between 2014 and 2019, the Ajuntament de Barcelona ran three partially overlapping digitisation programmes — the Pla de Barris asset inventory, the Cadastre integration project carried out in partnership with Spain's Dirección General del Catastro, and an early iteration of what became the Habitatge.cat portal — each of which ingested property photographs using different file-naming conventions and without a shared deduplication protocol. Images uploaded by landlords applying for tourist licence renewals on the Via Laietana licensing office's old web form were stored in a separate bucket from those uploaded by social housing applicants at the Oficina de l'Habitatge in Nou Barris.

When the city merged those data streams into a single Unified Housing Register — formally launched in March 2023 — engineers discovered that duplicate-image rates in certain postal districts ran as high as 23 percent, according to internal documentation reviewed by The Daily Barcelona. Eixample, which contains Spain's densest concentration of Airbnb-style tourist apartments, accounted for a disproportionate share of the anomalies, largely because landlords had re-used the same professionally staged photographs across multiple licence applications over several years.

The short-term rental boom amplified everything. Between 2017 and 2023, the number of active tourist flat licences in Barcelona never fell below 9,500, and applications generated a constant flow of new images being appended to existing property records. The Consorci de l'Habitatge de Barcelona, which coordinates housing policy between the city and the Generalitat de Catalunya, estimates that at peak flow, roughly 800 new property images a month were being added to the unified register — with no automated check against existing entries.

What Happens Next

The Ajuntament confirmed in a June 2026 tender notice published in the Butlletí Oficial de la Província de Barcelona that it is procuring a dedicated image-deduplication contract valued at up to €340,000. The shortlisted approach uses perceptual hash algorithms — technology that identifies visually similar images even when file metadata differs — to flag suspect records for human review. Pilot testing began in April in the Poblenou district, chosen partly because its mixed industrial-residential stock makes false positives easier to identify manually.

For tenants and landlords, the practical consequence is straightforward: any property inspection request submitted to the Oficina de l'Habitatge at Carrer del Bisbe Laguarda 2 in the Eixample will now be cross-checked against the deduplication output before an inspector is dispatched. The city says it expects to clear the backlog of flagged records before the end of 2026, putting the unified register in a cleaner state ahead of the January 2027 deadline by which all non-renewed tourist apartment licences must be surrendered. Whether the procurement timeline holds will depend on how many of those 140,000-plus records need manual adjudication once the algorithm finishes its first full pass.